Police fired tear gas Friday at demonstrators gathered for a fourth straight day of protests over a coal power plant in the southern Chinese town of Haimen and for the release of villagers detained during earlier scuffles with authorities.

Video from CNN affiliate i-CABLE News showed a large group of protesters running from clouds of tear gas on a main street. The Hong Kong-based cable network later reported that its reporting team was being detained by police.

Thousands of protesters gathered at the entrance of a local expressway, according to Zheng, a local resident who declined to give his full name for fear of being identified by authorities. Police blocked the expressway entrance several days ago and maintain a heavy presence there.

The protests began Tuesday morning when a group of residents went to the local government with a petition asking for the removal of the power plant and to stop the construction of a second.

When they did not get a response, they gathered on a street outside the government building. Some people were beaten.

China's state-run Xinhua news agency reported the protests were sparked by plans to expand the coal-fired power plant.

"Villagers complained that the current power plant had led to a rise in the number of cancer patients, the deterioration of the environment and a drop in fishing hauls," according to Xinhua.

The Shantou city government said Tuesday the project would be suspended, the news agency said.

Protests have been on the rise in China, where public displays of dissatisfaction are typically rare. The protests are driven by socioeconomic issues like income inequality, corruption, pollution and inflation, according to the U.S.-China Economic and Security Review Commission.